It is often desirable to reduce the speed of products carried by a conveyor in a certain area of the conveyor without changing the speed of objects on the remainder of the conveyor or changing the speed of the conveyor itself. Such control of the speed of the objects conveyed is useful when it is desirable to achieve, e.g., an orderly merging of two or more lines of objects into a single line; a uniform decrease or increase in spacing in objects in a single line; rotation of objects on the conveyor; holding or stalling of the objects. Previously it has been suggested that a friction plate be brought in contact with the bottoms of rollers linked together in a moving belt in order to cause the roller to rotate and move the objects forward faster on the belt. Such a technique can only speed up the forward speed of the objects relative to the moving belt: it can not slow down, halt, or reverse their direction. Further, the increase in speed is not controllable but fixed by the speed of the conveyor and diameter of the rollers.